Rotary drier



May 31, 1932. w. A. HARTY ET AL ROTARY DRI ER Original Filed April 23.1928 aented May "31, 19,32

UNITED STATES PATENT OFFICE WILLIAI A. HABTY, F BUFFALO, NEW YORK, ANDFRANK W. MOORE, 0F THOROLD,

ONTARIO, CANADA, ASSIGNORS, BY MESNE ASSIGNMENTS, TO THE W. S. COHPANY,0F CLEVELAND, OHIO, A CORPORATION 0F OHIO TYLER ROTARY DRIE'B.

Application led April 23, 1928, Serial No. 272,269. Renewed .Tune 1,1931.

This invention relates to rotary driers of the hot mandrel type such asis illustrated in our prior patents Reissue #16.265 of February 6, 1926,and #1,5873 27 of June 8, 1926, and is in part a division of our priorapplication SerialNo. 228,212, being particularly directed to the heatreturn deflector or baille which may be provided as an attachment forour driers and which utilizes the exhaust heat o from the hot core ormandrel to increase the o rating eiiiciency of the drier by returning te heat hearing gases back through the drier thereby not only augmentingthe drying action but carrying oif the vapors created by the more orless wet material placed in the drier at the intake end thereof.

The construction and operation of our drier is described and illustratedin the aecompanying specification and drawings, and the characteristicfeatures of novelty are particularly pointed out in the appended claims.In the drawings:

Fig. 1 is a side elevation, partly in section, of a drier assembly inaccordance with our general type and equipped with the device of thepresent invention.

Fig. 2 is an end view of the driershell as seen from the right of Fig.l, the blower fan being omitted, and

Fig. 3 in a fragmentary section showing a rodified form of heat returndeiieetor or ba e.

We have indicated at 1 the rotary shell and at 2 the internal hollowcore or hot mandrel which rotates with said shell and which ischaracteristic of our drier.

The mandrel preferably extends the full lengt-h of the shell and bot-hshell and mandrel may be in sections for convenience of shipment orreplacement ofparts.

In order to keep the material in its travel in direct contact with thehot surface of the mandrel, the mandrel is provided with longitudinallyextending heat-radiating ribs 2. and the shell is provided interior-lythereof with a plurality of lifting flanges 1 which lift the materialbeing dried and cascade it onto the hot mandrel.

As in our said prior application, the shell sect-ions are provided withcircumferential tires 3 running on suitable rollers on the supports forthe drier. If the metal supporting 'bases 4 and 5 shown in thesedrawings are used as supports for the shell, the tires run on a pairof-spaced vertically disposed rollers 6 mounted on the base frames.These rollers may conveniently serve as ground wheels when the bases areup-ended and used as Wheeled trucks for moving the bases from place toplace.

The drier shell may be rotated from. any suitable power source. lVhere abase such as the base 4 is used, the shell isv directly driven from anelectric motor M mounted on said base. The motor shaft 7 carries a,sprocket 8. which through chain 9 drives a sprocket l0 on one oftheshell sections.

As in our said prior application the mandrel sections tclescopically fitone within the other and are suspended within the shell by means of aplurality of spring suspension members l5 which are specially designedto overcome the effects of expansion and contraction.

The drier may be heated in any suitable manner as by oil, gas. steam orpowdered fuel. le have shown it as oil fired in these drawings by meansof the burner nozzle 1l discharging directly into the firing end of themandrel.

As contemplated herein, the exhaust heat from the mandrel is returnedthrough the space'betwecn the mandrel and shell with a resultantincrease of drying emciency. The exhaust. hcat returned also serves tocarry ofi'. at thc firing or intake end of the drier, an)v7 vapors gircnofi' b v thc more or less wct material being fed into the drier at saidintakt` end. To accomplish this result we mount, prcfcral'ilydctacllably, over thc eX- of a member having a central forwardlydirected curved or pointed portionl 12 alined with the mandrel landagainst which theexhaust heat from the mandrel discharges and by reasonof which eddy currents are reduced, and an enclosing reversely curvedrtion 12 substantially spanning the space ggtween the mandrel and outershell and by means of which such exhaust heat is returned back throughthe space between the mandrel and shell towards the firing end of thedrier. This return may be assisted, if desired, by the blower fan F,which is mounted at this end of the shell. It will be noted thatprojecting the dame into the central tube which serves as a combustionchamber as shown in Fig. 1 of our drawings creates a ressure in thegases contained within this tube. These gases then travel down thecentral tube to the heat deflecting baille where their direction of flowis sharply reversed. The ycentrifugal force involved by this sharp turncauses the gases to hang to the inside curved surface of the defiectingbaffle, thereby constricting the effective area through which they passand forming a jet of swiftly moving gases across the annular space beltween the lip of the deflecting baille and the outer shell, striking theouter shell at such an angle that they rebound'towards the firing end ofthe drier.- The formation of this ist results in a change in thepressure conditions existing in the gases, the static pressure which wasin the central tube being converted into velocity pressure, andas thegases pass on back betweenthe inner and outer shells they again slowdown, re-converting the velocity pressure generated at 'the time ofreversal of flow into static pressure. This allows the material whichhas been dried to flow out through the annular orice between the heatdeflector and the outer shell without allowing the gases from within theinner shell to escape at this point-in any substantial amount` as theonly available outlet at this end of the drier is scaled by said iet, asdescribed above. This obviates the necessity of using any form ofmechanical air lock. Also, it is clear that by means of the action ofour baille the static pressure within the inner shell is passedA on tothe annular space between the two shells. This establishes a positiveiow of those gases to any point of exit that may be provided for themand, as our drawings show, such an exit is provided at the feed end ofthe drier. The ilow thus set up clears the drying chamber of theproducts of evaporation and causes the hot gases to dow back through andin direct contact with the material which is drymg. v

The'bale 12 in Figs. 1 and 2 may be mounted over the exhaust end of themanmethod of mounting the baille may obviously be resorted to if withinthe spirit and Scope of our invention as defined by the appended claims.y

What we therefore claim and desire `to secure by Letters Patent is: y,

1. A drier comprising aced inner and outer shells both continuous y openfrom end to end, means for projectin drying heat into one end of saidinner she l, and a bale spaced from the exhaust end of said inner shelland substantially spanning the space between said shells for returningsubstantially all of the hot gases discharging from the inner shell incounter-current relation through the space between said `shells and overthe material therein to be dried, said bale formed to present aforwardly directed central portion alined with the inner shell and anenclosing heat return portion.

2. A drier comprising aced inner and outer shells forming two c ambers,one of which is a drying chamber and the other of which is a combustionchamber, each end of said drying chamber being open and oieringsubstantially unobstructed passageways for the material to enter and.leave the drying chamber, means for forcingafcombustible mixture intosaid combustion chamber, and means at one end of said combustion chambersubstantially spanning the end of the drying chamber for directing gasesilowin from said combustion chamber toward the en of the drying chamberat which; said combustible mixture is introduced into the combustionchamber.

s. A drier sa claimed in claim 2 whereinthe inner shell constitutes thecombustion chamber and the space between the inner nd outer shellsconstitutes the drying cham-l er. ,f

4. A drier as claimedin claim 2 wherein the gas d eecting means is abaie of mushroom sha e set at the discharge end of said inner shel withthe stem thereof pointing of said'shell. A

5. 'A drier of the class described, 'comprising in combination, an outermaterial into said open end of said shell along the axis i' exhaust endof said inner shell, of such a. dameter as to substantially span theouter shell and provided with an axially directed outer peripheralortion extending toward the opposite end o? said inner shell.

In testimony whereof we aix our signa tures.

WILLIAM A. HARTY. FRANK W. MOORE.

